Field of the Invention
The invention relates to a method for producing complementary MOS transistors and complementary bipolar transistors on the same semiconductor wafer, which includes producing buried zones of differing conductivity, producing n-doped and p-doped wells for corresponding transistors, and producing field oxide regions and insulated gate electrodes of the MOS transistors.
One such method is known, for instance, from European Patent Application 0 227 690 A. The production of devices with bipolar and MOS transistors is typically expensive and complicated, since transistors for analog signal processing, in particular, must have different properties from transistors for digital signal processing. The active regions of the bipolar and MOS transistors are therefore produced with a number of masks, in accordance with the properties to be attained. Further masks are needed if a resistor or a capacitor is to be integrated in addition. The connection of the active transistor regions to the associated metallizing lines must be provided in such a way that a reliable, low-impedance connection is produced.